Hp Yokes?

[KelpCoasters]

Hello all. First time tank owner question here:
I was given a 100cf steel tank for christmas and I'm a bit confused about the setup. The valve, which is a yoke, states a working pressure of 3442 psi. Are there such things as HP yokes? I was always under the impression that a HP steelie used a DIN valve only. Do I have a high pressure tank? Is it stated somewhere on the tank? It's a luxfer as far as I can tell.
Any help greatly appreciated. Thanks.

 

[DA Aquamaster]

It's probably a Pressed Steel Tank E7-100 if the working pressure is 3442 psi. They normally come with a convertible DIN/K valve with a removeable insert. I'd be really surprised if it were a regular K valve.

Most currently produced yokes are designed to be used with 3000 to 3300 psi tanks. Another 142 psi should not cause a problem as current yokes are pretty heavy with a good safety margin...but it really should be used with a DIN connection.

 

[Diver0001]

Yokes with that pressure range are fairly common in Europe. As DA Aquamaster said they're generally convertable to DIN, which is a good way to go. The yoke can take it but blown o-rings are common. When I dove tanks with these kinds of yokes I generally flipped the o-ring over after 5 dives and replaced them after 10 or so. That helped.

R..

 

[mart1]

What you guys in the USA call high pressure is not all that high.
In Europe we have old 200 bar tanks (3000 psi) and new 230 bar (3450 psi). Both are low pressure and can be used with a yoke connection.
And then we use 300 bar (4500 psi) tanks, now this is high pressure and can only be used with a DIN300 connection. You will also find DIN200 connections, which can only be used with low pressure

ciao, mart

 

[KOMPRESSOR]

What you guys in the USA call high pressure is not all that high.
In Europe we have old 200 bar tanks (3000 psi) and new 230 bar (3450 psi). Both are low pressure and can be used with a yoke connection.
And then we use 300 bar (4500 psi) tanks, now this is high pressure and can only be used with a DIN300 connection. You will also find DIN200 connections, which can only be used with low pressure

ciao, mart

Well, yes and no, I think... :14:

Even though 300 bar/4500 PSI tanks are common in Europe and certainly HP, I think the US divers have a different way of seeing it. From what I've understood they have tanks with even lower WP than 200 bar / 3000 PSI. So what they consider HP may very well be the 3442 PSI tank mentioned here.

But I may have misunderstood though... Anyone who could comment on this? What is US LP and US HP in PSI / BAR?

Up here north 300 bar is very common. In fact 10L/300 bar has been the most sold tank in the larger dive shops for the past years. But I think the long 12L/232 is the winner of the future

 

[DA Aquamaster]

2400 (2640 psi with a 10% overfill) tanks are popular and 2250 (2475) psi steel 72's are still in use as well. On rare occassions you will find an older 1800 or 2015 psi steel tank. All of those are considered "low pressure" as are 3000 and 3300 psi aluminum tanks.

Anything higher than 232 bar is considered high pressure, so the 3442 psi E7-100's just sneak in under the line.

 

[KOMPRESSOR]

2400 (2640 psi with a 10% overfill) tanks are popular and 2250 (2475) psi steel 72's are still in use as well. On rare occassions you will find an older 1800 or 2015 psi steel tank. All of those are considered "low pressure" as are 3000 and 3300 psi aluminum tanks.

Anything higher than 232 bar is considered high pressure, so the 3442 psi E7-100's just sneak in under the line.

Thank you! I'm old but I'm learning new stuff every day!

2400 PSI should be 160 BAR then? I suppose you need a pretty large tank then, to have enough air for anything but shallow dives...

 

[oxyhacker]

just to make things completely confusing, you will also sometimes see pressure ratings stamped on the yoke itself, as high as 4400 psi, and maybe even higher. These appear to be ratings for the yoke itself - not the interface. That is to say, the manufacturer is saying the yoke can stand that pressure, but not making any claims for the actual seal between the yoke and the valve or the advisability of using it with such a pressure.

The 3442 psi rating on many new tanks is not just random - they are designed for the highest possible pressure still be able to use a 230 bar "international outlet" dual DIN/Yoke convertible valve. This makes a lot of sense compared with having to buy a special valve or manifold that fits nothing else, as the original HP steels required, so it's a good tradeoff for the 58 psi you lose compared to a true 3500 psi tank.

 

[KelpCoasters]

So I guess what I really want to know is: How much more bottom time will I gain from this tank than a LP AL 80?

Is everybody pretty much recommending that I get a DIN valve put on this tank?

There is also a tag that says 70 degrees on the valve. What does this temperature mean?

Thanks and Merry Christmas.

 

[KOMPRESSOR]

So I guess what I really want to know is: How much more bottom time will I gain from this tank than a LP AL 80?

Is everybody pretty much recommending that I get a DIN valve put on this tank?

There is also a tag that says 70 degrees on the valve. What does this temperature mean?

Thanks and Merry Christmas.

1. I don't know, since you guys never refer to the dead volume of the tank, but rather give the volume of the air you can fill it with. Just compare the cui, can't you? We are metric, and have an easy time figuring out the totals when comparing tanks.
   
2. Yes, get DIN valves. They are more solid and have less parts. And you can always get a conversion if you travel to some weird place where they don't have modern valves!
   
3. The temp is a factor when the tank is certified to a certain pressure, and it refers to the given pressure at this temperature. If you'd had your tanks filled outdoors in Alaska in January you'd se the pressure rise if you put the tank next to the woodstove...